169,772 research outputs found
Discussion: Response of a plastic pipe buried in expansive clay
No full textResponse to discussion on Gallage CPK, Chan D and Kodilara J (2012) Response of a plastic pipe buried in expansive clay. Proceedings of ICE, Geotechnical Engineering, Vol 164, February 2012, Issue GE1, pages 45-57
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Formation of the three-dimensional geometry of the red blood cell membrane
No full textRed blood cells (RBCs) are nonnucleated liquid capsules, enclosed in deformable viscoelastic membranes with complex three dimensional geometrical structures. Generally, RBC membranes are highly incompressible and resistant to areal changes. However, RBC membranes show a planar shear deformation and out of plane bending deformation. The behaviour of RBCs in blood vessels is investigated using numerical models. All the characteristics of RBC membranes should be addressed to develop a more accurate and stable model. This article presents an effective methodology to model the three dimensional geometry of the RBC membrane with the aid of commercial software COMSOL Multiphysics 4.2a and Fortran programming. Initially, a mesh is generated for a sphere using the COMSOL Multiphysics software to represent the RBC membrane. The elastic energy of the membrane is considered to determine a stable membrane shape. Then, the actual biconcave shape of the membrane is obtained based on the principle of virtual work, when the total energy is minimised. The geometry of the RBC membrane could be used with meshfree particle methods to simulate motion and deformation of RBCs in micro-capillaries.
References J. B. Freund and H. Zhao. A High-Resolution Fast Boundary-Integral Method for Multiple Interacting Blood Cells. In Computational Hydrodynamics of Capsules and Biological Cells, page 71. Chapman and Hall, 2010. C. Pozrikidis. Numerical simulation of the flow-induced deformation of red blood cells. Ann. Biomed. Eng., 31(10):1194–1205, 2003. doi:10.1114/1.1617985 D. A. Fedosov, B. Caswell, and G. E. Karniadakis. A multiscale red blood cell model with accurate mechanics, rheology, and dynamics. Biophys. J., 98(10):2215–2225, 2010. doi:10.1016/j.bpj.2010.02.002 H. N. P. Gallage, Y. T. Gu, S. C. Saha, W. Senadeera, and A. Oloyede. Numerical simulation of red blood cells' motion : a review. In Y. T. Gu and S. C. Saha, editors, 4th International Conference on Computational Methods (ICCM 2012), Crowne Plaza, Gold Coast, QLD, November 2012. T. W. Pan and T. Wang. Dynamical simulation of red blood cell rheology in microvessels. Int. J. Numer. Anal. Mod., 6:455–473, 2009. K. I. Tsubota, S. Wada, H. Kamada, Y. Kitagawa, R. Lima, and T. Yamaguchi. A particle method for blood flow simulation: application to flowing red blood cells and platelets. Journal of the Earth Simulator, 5:2–7, 2006. http://www.jamstec.go.jp/esc/publication/journal/jes_vol.5/index.html H. N. P. Gallage, Y. T. Gu, S. C. Saha, W. Senadeera, and A. Oloyede. Numerical simulation of red blood cells' deformation using sph method. In Y. T. Gu and S. C. Saha, editors, 4th International Conference on Computational Methods (ICCM 2012), Crowne Plaza, Gold Coast, QLD, November 2012. T. W. Secomb, B. Styp-Rekowska, and A. R. Pries. Two-dimensional simulation of red blood cell deformation and lateral migration in microvessels. Ann. Biomed. Eng., 35(5):755–765, 2007. doi:10.1007/s10439-007-9275-0 K. I. Tsubota and S. Wada. Elastic force of red blood cell membrane during tank-treading motion: Consideration of the membrane's natural state. Int. J. Mech. Sci., 52(2):356–364, 2010. doi:10.1016/j.ijmecsci.2009.10.007 M. Bessis. Red Cell Shapes. An Illustrated Classification and its Rationale. In M. Bessis, R. I. Weed, P. F. Leblond, Eds., Red Cell Shape, pages 1–25. Springer Berlin Heidelberg, 1973. doi:10.1007/978-3-642-88062-9_1 K. Tsukada, E. Sekizuka, C. Oshio, and H. Minamitani. Direct measurement of erythrocyte deformability in diabetes mellitus with a transparent microchannel capillary model and high-speed video camera system. Microvasc. Res., 61(3):231–239, 2001. doi:10.1006/mvre.2001.230
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Impact resistance and evaluation of retained strength on geotextiles
No full textOver the last few decades, geotextiles have progressively been incorporated into geotechnical applications,\ud
especially in the field of coastal engineering. Geotextile materials often act as separator and a filter\ud
layer between rocks laid above and subgrade beneath. This versatile material has gradually substituted\ud
traditional granular materials because of its ease of installation, consistent quality and labour costefficiency.\ud
However, geotextiles often suffer damage during installation due to high dynamic bulk\ud
loading of rock placement. This can degrade geotextiles' mechanical strength. The properties considered\ud
in this paper include the impact resistance and retained strength of geotextiles. In general, the greater\ud
the impact energy applied to geotextiles, the greater the potential for damage. Results highlight the\ud
inadequacy of using index derived values as an indicator to determine geotextile performance on site\ud
because test results shows that geotextiles (staple fibre (SF) and continuous filament (CF)) with better\ud
mechanical properties did not outperform lower mechanical strength materials. The toughest CF product\ud
with a CBR index value of 9696N shows inferior impact resistance compared to SF product with the least\ud
CBR strength (2719N) given the same impact energy of 9.02 kJ. Test results also indicated that the\ud
reduction of strength for CF materials were much greater (between 20 and 50%) compared to SF materials\ud
(between 0 and 5%) when subjected to the same impact energy of 4.52 kJ
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Benchmark studies for bridge health monitoring using an improved modal strain energy method
No full textInsufficient available dynamic characteristics data of real structures during the service and prior to damage is a concern in Structural Health Monitoring (SHM) employing Vibration Based Damage Detection (VBDD) techniques. The issue becomes more intense with complexity of the structure. One remedy for this problem is to apply new methodologies to the same structure as the benchmark structure having measured data available at different cases. Hence, the reliability of the proposed approach is typically confirmed in reality for that type of structures. This study aims to examine the application of an improved two-stage Modal Strain Energy (MSE) method to a benchmark bridge available, whereas the MSE method has already been numerically and experimentally verified. For this purpose, a steel truss bridge model is numerically simulated. Different damage scenarios, affected by up to five percent noise are considered and the first five vertical mode shapes are used. The results show that the proposed method is proper for health monitoring of complex bridges and accurately identifies the damage in the bridge model under consideration. The findings of this paper can confidently contribute to academic studies and the bridge industry to realize the genuine condition and behaviour of complex bridges during the damage
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
- …
